A main arch structure for a concrete-filled steel tube tied arch bridge and a construction method thereof

Abstract

This application relates to a main arch structure for a steel-concrete composite tied arch bridge and its construction method, belonging to the technical field of bridge structures. The main arch structure includes two arch abutments, several arch sections disposed between the two arch abutments, and a reinforcing structure disposed at the connection between adjacent arch sections. The several arch sections are sequentially connected to form an arch shape, with the arch sections at both ends connected to the two arch abutments. The reinforcing structure includes two sets of mounting components respectively connected to two adjacent arch sections and reinforcing rods that fix the two sets of mounting components together. By adding a reinforcing structure at the connection between adjacent arch sections, the connection between the arch sections is strengthened, making the connection between the arch sections more robust and tighter, resulting in higher stability and robustness of the entire main arch structure and stronger resistance to deformation.

Description

Technical Field

[0001] This application relates to the technical field of bridge structures, and in particular to a main arch structure for a steel-concrete composite tied arch bridge and its construction method. Background Technology

[0002] As a member of the arch bridge family, the tied-arch bridge possesses the general characteristics of arch bridges while also exhibiting its own unique features. It is a bridge type that combines the advantages of both arches and beams, integrating the two basic structural forms to jointly bear loads. It fully utilizes the structural performance and combined effect of beams bearing bending and arches bearing compression. Horizontal thrust at the arch ends is borne by tie rods, preventing horizontal thrust from being generated at the arch end supports. The arch and chord are connected by vertical rods hinged at both ends; alternatively, diagonal rods can be used instead of vertical rods, forming a Nelson system. This type of arch bridge is internally statically indeterminate and externally statically determinate, thus having no effect on uneven settlement of the piers and abutments.

[0003] As an excellent steel-concrete composite structure bridge, steel-concrete composite arch bridges have seen rapid development in recent years. The main arch web members of steel-concrete composite truss arch bridges are mainly arranged in an "N-shape". The angle between the diagonal web members and the axis of the main arch is generally 30° to 60°. The free length of the web members in this arrangement is greater than or equal to the height of the main arch section, and the free length of the web members is generally 1.15 to 2 times the height of the main arch section.

[0004] As the span of steel-concrete composite arch bridges continues to increase, the main arch structure of tied arch bridges becomes unstable, increasing the difficulty of installation and bringing more challenges to the construction of tied arch bridges, thus extending the construction period. Summary of the Invention

[0005] The purpose of this application is to provide a main arch structure for a steel-concrete composite tied arch bridge and its construction method, which provides a stable installation structure, reduces installation difficulty, and makes construction safer and more reliable.

[0006] Firstly, the technical solution provided in this application for the main arch structure of a steel-concrete composite tied arch bridge adopts the following:

[0007] A main arch structure for a steel-concrete composite tied arch bridge includes two arch abutments, several arch sections disposed between the two arch abutments, and a reinforcing structure disposed at the connection between adjacent arch sections.

[0008] Several arch sections are connected in sequence to form an arch shape. The arch sections at both ends are connected to two arch seats. The reinforcing structure includes two sets of mounting components connected to two adjacent arch sections respectively, and a reinforcing rod that fixes the two sets of mounting components.

[0009] By adopting the above technical solution, a reinforcing structure is added at the connection between adjacent arches. Based on the connection between adjacent arches, the reinforcing structure is used to strengthen the connection between adjacent arches, making the connection between arches more solid and tight. The stability and solidity of the entire main arch structure are higher, and the resistance to deformation is stronger.

[0010] Optionally, the arch includes two sets of parallel and oppositely arranged single-row frames. Each single-row frame includes an upper chord, a lower chord, and a web member connecting the upper and lower chords. Ribs are connected between the upper chords and the lower chords of the two sets of single-row frames. Adjacent arches are connected by the upper and lower chords.

[0011] By adopting the above technical solutions, the arch structure becomes more stable, has high structural strength, is less prone to deformation, and the strength of the main arch structure is improved.

[0012] Optionally, the mounting assembly includes an upper sleeve fitted onto the upper chord tube, a lower sleeve fitted onto the lower chord tube, and a connecting plate connecting the upper sleeve and the lower sleeve, with a reinforcing rod connected between the two connecting plates.

[0013] By adopting the above technical solution, the installation components can connect the upper and lower chords of the arch, enhance the stability between the ends of the upper and lower chords, prevent deformation of the ends of the upper and lower chords, and connect the two installation components with reinforcing rods, further improving the structural strength of the arch connection.

[0014] Optionally, the reinforcing rod is bolted to the connecting plate, and several connecting holes are provided at both ends of the reinforcing rod along the length direction, and the connecting bolts can be adjusted to pass through different connecting holes.

[0015] By adopting the above technical solution, the connection position between the reinforcing rod and the connecting plate is adjustable, which allows the installation positions of the upper and lower sleeves to be adjusted, avoiding the position of the web rod and making it easier to install the components.

[0016] Optionally, a partition plate is provided at the end of the upper chord tube of the arch with the greatest height. The partition plate divides the interior of the upper chord tube, which gradually decreases in height on both sides, into grouting chambers. A grouting pipe is provided on the bottom upper chord tube of the grouting chamber, and a grout outlet pipe is provided on the top upper chord tube of the grouting chamber.

[0017] The structure on the lower chord is the same as the structure on the upper chord.

[0018] By adopting the above technical solution, grouting chambers are formed inside the upper and lower chord pipes. Mortar concrete is injected into the grouting chambers from the lower grouting pipe until the mortar concrete emerges from the grout outlet pipe. The arch body adopts a steel pipe concrete structure to enhance the strength of the structure.

[0019] Optionally, vent holes are provided on the upper and lower chords of the slurry outlet pipe, and the height of the vent holes is lower than the height of the slurry outlet pipe.

[0020] By adopting the above technical solution, air in the injection mortar concrete is discharged through the vent hole, thereby improving the injection quality of the mortar concrete.

[0021] Secondly, the construction method for the main arch structure of a steel-concrete composite tied arch bridge provided in this application adopts the following technical solution:

[0022] A construction method for the main arch structure of a steel-concrete composite tied arch bridge includes the following steps:

[0023] Secure the arch to the top of the bridge pier;

[0024] Install inclined-stayed towers on top of the arches other than those at both ends;

[0025] Install ground supports at the corresponding positions below the arch body near the arch abutments at both ends, and gradually increase the height of the ground supports as the height of the arch body increases.

[0026] Multiple main arch structures are constructed in the order of construction from both ends to the middle, while a single main arch structure is constructed in the order of construction from both ends to the middle.

[0027] During the construction of the end main arch structure, the two lowest arch bodies are fixed to the two arch seats respectively. The two second lowest arch bodies are installed by moving one to the ground support and connecting it to the lowest arch body, and suspending the other to the cable-stayed tower and connecting it to the lowest arch body through the cable. The arch bodies are installed in the same way to increase in height until the main arch structure is capped.

[0028] During the construction of the non-end main arch structure, the two lowest arch bodies are fixed to the two arch seats respectively. The two second lowest arch bodies are installed by suspending them on the cable-stayed tower and connecting them to the lowest arch body. The arch bodies are installed in the same way to increase in height until the main arch structure is capped.

[0029] Dismantle the cable-stayed tower and the ground support.

[0030] By adopting the above technical solutions, the installation of the main arch structure uses a construction method of ground support combined with inclined cable ties, which can improve the safety and stability of the main arch structure installation process. In particular, the efficiency of the installation process of multiple main arches is significantly improved.

[0031] Optionally, the main arch structure can be installed using a bridge deck gantry crane. The arch body is not carried on the bridge. After being transported from the ground or trestle to the installation location, it is hoisted to the installation location by passing through the space of the main beam structure.

[0032] By adopting the above technical solution and using a gantry crane to lift the arch, the lifting process is safer and the arch is more stable. Lifting from the ground or trestle can more conveniently and quickly transport the arch to the installation position, improving the installation efficiency of the entire main arch structure and avoiding damage to the bridge beams.

[0033] Optionally, each arch is provided with at least two tension points from the cable tie, and as the height of the installed arch increases, the height of the connection point between the corresponding cable tie and the cable-stayed tower on the arch gradually increases.

[0034] By adopting the above technical solutions, the distribution of the cable ties is more organized, preventing tangling and improving the safety of the construction process. The stress distribution of the cable-stayed tower is more reasonable and safer.

[0035] Optionally, before dismantling the cable-stayed tower and the ground support, it is necessary to perform mortar concrete injection inside the arch. The injection process includes:

[0036] Mixing of mortar and concrete;

[0037] Arch line measurement:

[0038] Holes were drilled on the upper and lower chord pipes respectively to install grouting pipes and grout outlet pipes;

[0039] Clean the dirt inside the grouting chamber and moisten the inner wall of the grouting chamber;

[0040] Grouting chamber is filled with mortar and concrete and the arch shape is measured until grout comes out of the grout outlet pipe;

[0041] Close the grouting pipe and stabilize the pressure inside the grouting chamber;

[0042] Dismantle the grouting pipe and grout outlet pipe to complete the grouting process;

[0043] Repair the openings on the upper and lower chords.

[0044] In summary, this application includes at least one of the following beneficial technical effects:

[0045] 1. Add a reinforcing structure at the connection between adjacent arches. Based on the connection between adjacent arches, use the reinforcing structure to strengthen the connection between the arches, making the connection between the arches more solid and tight, and the stability and solidity of the entire main arch structure are higher, and the resistance to deformation is stronger.

[0046] 2. The mounting components connect the upper and lower chords of the arch, enhancing the stability between the ends of the upper and lower chords and preventing deformation at the ends of the upper and lower chords. The use of reinforcing rods to connect the two mounting components further enhances the structural strength of the arch connection.

[0047] 3. The main arch structure in this application is installed using a ground-supported bracket combined with a diagonal bracing method, which can improve the safety and stability of the main arch structure during installation, and significantly improve the efficiency of the installation of multiple main arches. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of a single main arch structure in Embodiment 1 of this application;

[0049] Figure 2 This is a schematic diagram of the connection state between the arch and the reinforcing structure in Embodiment 1 of this application;

[0050] Figure 3 This is a schematic diagram of the grouting chamber structure in Embodiment 1 of this application;

[0051] Figure 4 This is a schematic diagram of the installation process of multiple main arch structures in Embodiment 2 of this application. Figure 1 ;

[0052] Figure 5 This is a schematic diagram of the installation process of multiple main arch structures in Embodiment 2 of this application. Figure 2 :

[0053] In the diagram, 1. Arch seat; 2. Arch body; 21. Upper chord; 22. Lower chord; 23. Web member; 24. Rib; 25. Grouting pipe; 26. Grout outlet pipe; 3. Reinforcing structure; 31. Reinforcing rod; 32. Upper sleeve; 33. Lower sleeve; 34. Connecting plate; 4. Cable-stayed tower; 5. Ground support; 6. Cable tie; 7. Gantry crane. Detailed Implementation

[0054] The following is in conjunction with the appendix Figure 1 - Appendix Figure 5 This application will be described in further detail below.

[0055] Example 1: A main arch structure for a steel-concrete composite tied arch bridge, referring to... Figure 1 and 2 In this embodiment, a main arch structure is taken as an example, which includes two arch bases 1, several arch sections 2, and several sets of reinforcing structures 3. The arch base 1 is a trapezoidal concrete structure, with its bottom fixed to the top of the pier. The arch sections 2 are fixed to the inclined slope of the arch base 1. Several arch sections 2 are connected end to end to form an arch shape. The arch sections 2 at both ends are connected to the two arch bases 1. The end faces of the arch sections 2 are welded or connected by connecting flanges. The reinforcing structures 3 are connected at the connection points of adjacent arch sections 2 to strengthen the connection points of the arch sections 2. In this embodiment, reinforcing structures 3 are provided on both sides of the arch section 2.

[0056] The arch 2 includes two sets of parallel and oppositely arranged single-row frames. Each single-row frame includes an upper chord tube 21, a lower chord tube 22, and a web member 23. Both the upper chord tube 21 and the lower chord tube 22 are arc-shaped hollow round tubes. Multiple web members 23 are provided, connected between the upper chord tube 21 and the lower chord tube 22, and distributed in an N-shape. The two sets of single-row frames are connected by ribs 24. The ribs 24 connect the upper chord tubes 21 of the two sets of single-row frames and the lower chord tubes 22 of the two sets of single-row frames. When adjacent arches 2 are connected, they are connected by the upper chord tubes and the lower chord tubes.

[0057] The reinforcing structure 3 is installed on the outside of the two sets of single-row frames, with one set on each side. Each set of reinforcing structure 3 includes two sets of mounting components and one reinforcing rod 31. The two sets of mounting components are respectively connected to two adjacent arches 2, and the reinforcing rod 31 is fixedly connected between the two sets of mounting components. The mounting components include an upper sleeve 32, a lower sleeve 33, and a connecting plate 34. The upper sleeve 32 is fitted onto the end of the upper chord tube 21, and the lower sleeve 33 is fitted onto the end of the lower chord tube 22. The two ends of the connecting plate 34 are connected to the outer walls of the upper sleeve 32 and the lower sleeve 33. The upper sleeve 32, the lower sleeve 33, and the connecting plate 34 are installed as a whole, and the reinforcing rod 31 is connected between the two connecting plates 34. In this embodiment, the reinforcing rod 31 and the connecting plate 34 are detachably connected. The connecting plate 34 has a connecting hole, and the two ends of the reinforcing rod 31 also have several connecting holes along the length direction. The bolts pass through the connecting holes on the connecting plate 34 and the reinforcing rod 31 respectively and are fixed. The connecting bolts can pass through different connecting holes on the reinforcing rod 31, which makes the installation position of the upper sleeve 32 and the lower sleeve 33 adjustable and can avoid the position of the web rod 23.

[0058] Reference Figure 3 In this embodiment, the number of arch bodies 2 in a main arch structure is odd, with the middle arch body 2 having the greatest height. A partition plate is installed at the end of the upper chord tube 21 of the tallest arch body 2. The partition plate divides the interior of multiple upper chord tubes 21, which gradually decrease in height on both sides, into grouting chambers for injecting mortar concrete. Each grouting chamber has an opening on the bottom upper chord tube 21 connected to a grouting pipe 25, and an opening on the top upper chord tube 21 connected to a grout outlet tube 26. Both the grouting pipe 25 and the grout outlet tube 26 are detachably connected, allowing mortar concrete to be injected into the grouting chamber from the lower grouting pipe 25 until it emerges from the grout outlet tube 26. In this embodiment, an vent hole is provided on the upper chord tube 21 with the grout outlet tube 26. The vent hole is positioned lower than the grout outlet tube 26 to expel air from the injected mortar concrete, improving the quality of the mortar concrete injection.

[0059] In this embodiment, the grouting structure provided on the lower chord 22 is the same as the grouting structure provided on the upper chord 21, which facilitates the injection of mortar concrete into the grouting chamber formed by the lower chord 22.

[0060] Example 2: A construction method for the main arch structure of a steel-concrete composite tied arch bridge, applied to the construction of multiple continuous main arch structures, referencing... Figure 4 and 5 This includes the following steps:

[0061] S1. Construct arch seat 1 on top of the bridge pier;

[0062] S2. Install inclined cable towers 4 on the top surface of the arches 1 except for the arches 1 at both ends. The inclined cable towers 4 are vertical steel frame structures. Steel anchor beams are set on the inclined cable towers 4, and anchor cables 6 are tensioned and fixed. Low-stress wedge anchors are used, and the tensioning is done by group anchors. The wedges are locked by pressure plates. The safety factor of the cable 6 is 3.

[0063] S3. Install a ground support 5 at the corresponding position below the arch body 2 of the arch seat 1 near both ends, and the height of the ground support 5 gradually increases as the height of the arch body 2 increases.

[0064] S4. Construct multiple main arch structures in the order of construction from both ends to the middle, and install arch body 2 of a single main arch structure in the order of construction from both ends to the middle.

[0065] S5. During the construction of the end main arch structure, the two lowest arch bodies 2 are fixed on the two arch seats 1 respectively. The two second lowest arch bodies 2 are installed in the following manner: one is moved to the ground support 5 and connected to the lowest arch body 2, and the other is suspended by the cable 6 to the cable-stayed tower 4 and connected to the lowest arch body 2. The height of the arch bodies 2 is increased and installed in the same way until the main arch structure is capped.

[0066] S6. During the construction of the non-end main arch structure, the two lowest arch bodies 2 are fixed on the two arch seats 1 respectively. The two second lowest arch bodies 2 are installed by suspending them on the cable-stayed tower 4 through the cable 6 and connecting them to the lowest arch body 2. The arch bodies 2 are installed in the same way to increase their height until the main arch structure is capped.

[0067] S7. After the main arch structure is installed, mortar concrete is injected into the grouting chamber formed in the arch body 2.

[0068] S8. After the mortar concrete injection is completed, remove the inclined cable-stayed tower 4 and the ground support 5.

[0069] The process of injecting mortar concrete also includes the following steps:

[0070] Mix mortar and concrete, and transport them to the installation site;

[0071] Linear measurements were performed on arch body 2 to obtain data on the main arch structure:

[0072] Holes are drilled in the corresponding upper chord pipe 21 and lower chord pipe 22 using a hole-drilling device, and grouting pipe 25 and grout outlet pipe 26 are installed accordingly, while venting holes are retained.

[0073] Water is injected into the grouting chamber through the grouting pipe to clean the dirt inside the grouting chamber and moisten the inner wall of the grouting chamber;

[0074] Grout concrete is injected into the grouting chamber through the grouting pipe 25, and the linear shape of the arch 2 is measured intermittently to understand the linear change of the arch 2 until grout leakage occurs through the grout outlet pipe 26.

[0075] Close grouting pipe 25, stop grouting, and wait for the pressure in the grouting chamber to stabilize.

[0076] After the pressure is stabilized, remove the grouting pipe 25 and the grout outlet pipe 26 to complete the grouting work;

[0077] The openings on the upper chord tube 21 and the lower chord tube 22 can be sealed by welding.

[0078] In this embodiment, the main arch structure is installed using a bridge-mounted gantry crane 7. The arch body 2 is not mounted on the bridge; it is transported directly from the ground or trestle to the installation location and then hoisted to the installation position by passing through the space between the main beams of the bridge. The gantry crane 7 has self-lifting legs and an upward-folding cantilever design for the main beams, enabling convenient and rapid hoisting of the arch body 2 to the installation position, thus improving the overall installation efficiency of the main arch structure.

[0079] To ensure the stability of the arch 2 after installation, at least two tension points from the ties 6 are set above each arch 2. As the height of the installed arch 2 increases, the height of the connection position between the corresponding ties 6 on the arch 2 and the cable-stayed tower 4 also gradually increases. This makes the distribution of the ties 2 more orderly and prevents entanglement, thereby improving the safety of the construction process and making the stress situation of the cable-stayed tower 4 more reasonable and safer.

[0080] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A main arch structure for a concrete-filled steel tube tied-arch bridge, characterized by, It includes two arch bases (1), several arch sections (2) set between the two arch bases (1), and a reinforcing structure (3) set at the connection of adjacent arch sections (2); Several arch sections (2) are connected in sequence to form an arch shape. The arch sections (2) at both ends are connected to two arch seats (1). The reinforcing structure (3) includes two sets of installation components connected to two adjacent arch sections (2) and a reinforcing rod (31) that fixes the two sets of installation components. The arch section (2) includes two sets of parallel and oppositely arranged single-row frames. The single-row frame includes an upper chord tube (21), a lower chord tube (22), and a web member (23) connecting the upper chord tube (21) and the lower chord tube (22). Ribs (24) are connected between the upper chord tubes (21) and between the lower chord tubes (22) of the two sets of single-row frames. Adjacent arch sections (2) are connected by the upper chord tubes (21) and the lower chord tubes (22). The installation components include an upper sleeve (32) sleeved on the upper chord tube (21), a lower sleeve (33) sleeved on the lower chord tube (22), and a reinforcing rod (31) connected to the upper sleeve (32). 2) A connecting plate (34) is connected to the lower sleeve (33), and a reinforcing rod (31) is connected between the two connecting plates (34); the reinforcing rod (31) is bolted to the connecting plate (34), and several connecting holes are provided at both ends of the reinforcing rod (31) along the length direction, and the bolts can be adjusted to pass through different connecting holes; a partition plate is provided at the end of the upper chord pipe (21) of the arch body (2) with the largest height, and the partition plate divides the interior of the upper chord pipe with gradually decreasing height on both sides into grouting chambers. A grouting pipe (25) is provided on the bottom upper chord pipe (21) of the grouting chamber, and a grout outlet pipe (26) is provided on the top upper chord pipe (21) of the grouting chamber; the structure provided on the lower chord pipe (22) is the same as the structure provided on the upper chord pipe (21); an exhaust hole is provided on the upper chord pipe (21) and the lower chord pipe (22) with the grout outlet pipe (26), and the height of the exhaust hole is lower than the height of the grout outlet pipe (26).

2. The construction method for the main arch structure of a CFST tied-arch bridge according to claim 1, characterized in that, Includes the following steps: Fix the arch seat (1) to the top of the pier; Install inclined towers (4) on top of the arches (1) except for the arches (1) at both ends; Install ground support (5) at the corresponding position below the arch body (2) of the arch seat (1) near both ends, and the height of the ground support (5) gradually increases as the height of the arch body (2) increases; Multiple main arch structures are constructed in the order of construction from both ends to the middle, while a single main arch structure is constructed in the order of construction from both ends to the middle. During the construction of the end main arch structure, the two lowest arch bodies (2) are fixed on the two arch seats (1) respectively. The two second lowest arch bodies (2) are installed in the following manner: one is moved to the ground support (5) and connected to the lowest arch body (2), and the other is suspended by the cable (6) to the cable-stayed tower (4) and connected to the lowest arch body (2). The arch bodies (2) are installed in the same way until the main arch structure is capped. During the construction of the non-end main arch structure, the two lowest arch bodies (2) are fixed on the two arch seats (1) respectively. The two second lowest arch bodies (2) are installed by suspending them on the cable-stayed tower (4) through the cable (6) and connecting them to the lowest arch body (2). The arch bodies (2) are installed in the same way to increase their height until the main arch structure is capped. Remove the cable-stayed tower (4) and the ground support (5); the main arch structure is installed by a bridge deck gantry crane (7), the arch body (2) is not on the bridge, the arch body (2) is transported from the ground or trestle to the installation position, and then hoisted to the installation position by passing through the space of the main beam structure.

3. The construction method for the main arch structure of a steel-concrete composite tied arch bridge according to claim 2, characterized in that, Each arch (2) is provided with at least two tension points from the ties (6). As the height of the installed arch (2) increases, the connection height between the corresponding ties (6) on the arch (2) and the inclined cable tower (4) gradually increases.

4. A construction method for the main arch structure of a steel-concrete composite tied arch bridge according to claim 2, characterized in that, Before dismantling the cable-stayed tower (4) and the ground support (5), it is necessary to inject mortar concrete into the arch body (2). The injection process includes: Mixing of mortar and concrete; Arch (2) Linear Measurement: Holes are made on the upper chord pipe (21) and the lower chord pipe (22) respectively, and grouting pipe (25) and grout outlet pipe (26) are installed. Clean the dirt inside the grouting chamber and moisten the inner wall of the grouting chamber; Grouting concrete is poured into the grouting chamber and the shape of the arch (2) is measured until grout comes out of the grouting pipe (26); Close the grouting pipe (25) and stabilize the pressure inside the grouting chamber; Remove the grouting pipe (25) and the grout outlet pipe (26) to complete the grouting process; Repair the opening positions on the upper chord tube (21) and the lower chord tube (22).

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